How to activate Nexus 7. Screen stuck on X

[PTL]

Nexus 7 problem

[JK_Fiber_Art]

Some additional details would be helpful - please understand that the volunteer small business owners here are not the same as Tech or Customer Support.  Is the issue with Square's POS App and/or connecting to a Reader ?   Sorry we have to guess sometimes.  For example, there can be an issue with the first generation Google Nexus 7 tablet as it isn’t compatible with the Square Reader.  With updated firmware, the second generation Nexus 7 tablet (released August 2013) is supported.   Which generation do you have?   Hopefully with more info someone here may be able to provide some suggestions.